OBJECTIVE: To test the hypothesis that smooth muscle cells of the human umbilical vein have vasoconstricting endothelin B (ETB) receptors. METHODS: In strip preparations of human umbilical veins isometric tension after exposure to the selective ETB receptor agonist sarafotoxin S6c (S6c) was compared to the tension before S6c exposure (set as 100%). RESULTS: In intact preparations S6c induced vasoconstriction only at the highest concentration applied (10(-8)M; 149.5 +/- 12.5 vs. 100%, p < 0.05). In contrast, in endothelium-denuded preparations S6c induced vasoconstriction already at the lowest S6c concentration investigated (10(-11)M; 111.7 +/- 4.3 vs. 100%, p < 0.05). CONCLUSIONS: The vasoconstricting effect of S6c in endothelium-denuded human umbilical vein preparations points to smooth muscle cell ETB receptor activation. Copyright 2008 S. Karger AG, Basel.
OBJECTIVE: To test the hypothesis that smooth muscle cells of the human umbilical vein have vasoconstricting endothelin B (ETB) receptors. METHODS: In strip preparations of human umbilical veins isometric tension after exposure to the selective ETB receptor agonist sarafotoxin S6c (S6c) was compared to the tension before S6c exposure (set as 100%). RESULTS: In intact preparations S6c induced vasoconstriction only at the highest concentration applied (10(-8)M; 149.5 +/- 12.5 vs. 100%, p < 0.05). In contrast, in endothelium-denuded preparations S6c induced vasoconstriction already at the lowest S6c concentration investigated (10(-11)M; 111.7 +/- 4.3 vs. 100%, p < 0.05). CONCLUSIONS: The vasoconstricting effect of S6c in endothelium-denuded human umbilical vein preparations points to smooth muscle cell ETB receptor activation. Copyright 2008 S. Karger AG, Basel.
Authors: Andrew V Kuczmarski; Leena N Shoemaker; Joshua C Hobson; David G Edwards; Megan M Wenner Journal: Am J Physiol Heart Circ Physiol Date: 2020-06-19 Impact factor: 4.733